What are the signs that this is genuine?

I (M 33) have found myself in a new situation in which the guy (M 21) I'm talking to is significantly younger than I am. How do I know his intentions are true? How do I know his not yet fully matured prefrontal cortex isn't in the driver's seat of his belief that he wants to be with me? How do I know it's not a ploy to propel himself forward by a decade in the game of life by using my success to his advantage? I don't want to ask him these things, but an age gap relationship is new to me. When I brought it up today and said, "when I'm 40, you'll be 28," he said that's something to consider. Maybe I should just end this before I get hurt or played.